Sewing machine



FIG. 1 is a plan view of a sewing machine showing our new design;

FIG. 2 is a front view thereof;

FIG. 3 is a bottom view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a right side view thereof; and

FIG. 7 is a front perspective view thereof.

The ornamental design for a sewing machine, as shown.